1. Field of the Invention
The present invention relates to a method and an apparatus for manufacturing a semiconductor apparatus, and more particularly to a method of separating a semiconductor film and a substrate from each other.
2. Related Art
FIG. 10 shows a conventional method of manufacturing a semiconductor apparatus, and in particular, a method of separating a semiconductor film and a substrate from each other. The method has been disclosed in Japanese Patent Application No. 6-162452. Referring to FIG. 10, reference numeral 100 represents a semiconductor film, 120 represents a separation layer, 140 represents a substrate, and 110 represents a through hole reaching to the separation layer 120. Reference numeral 130 represents etchant and 130B represents water.
A method of separating the semiconductor film and the substrate from each other will now be described. The substrate 140 is made of silicon and formed into, for example, a single crystal silicon wafer. The thickness of the single crystal silicon wafer is usually 625 .mu.m in a case where the diameter of the wafer is 6 inches. A separation layer is provided which is made of a silicon oxide film formed by, for example, oxidizing the substrate 140 with heat or a silicon oxide film deposited by CVD or the like. The thickness of the separation layer is, for example, 1 .mu.m. The semiconductor film 100 is a polycrystal silicon film deposited on the separation layer by the CVD or the like. The semiconductor film 100 may be a semiconductor film having an improved electric characteristic by enlarging the crystal particle size by zone melting recrystallization or by solid phase epitaxy.
As shown in FIG. 10A, a semiconductor apparatus having the foregoing structure is, initially, immersed in, for example, hydrofluoric acid etchant 130A to introduce the hydrofluoric acid etchant 130A through the through holes 110 so as to remove the separation layer 120 by etching. Then, the semiconductor apparatus is washed with water, and then the space between the semiconductor film 100 and the substrate 140 is replaced with water 130B, as shown in FIG. 10B. In this state, water 130B acts like an adhesive agent between the semiconductor film 100 and the substrate 140 to prevent easy separation of the semiconductor film 100 from the substrate 140. If water 130B between the semiconductor film 100 and the substrate 140 is removed by allowing the semiconductor apparatus to stand or by drying the same with heat, the bonding state established between the semiconductor film 100 and the substrate 140 prevents natural separation of the semiconductor film 100.
Accordingly, when horizontal force is applied to the semiconductor film 100 along the surface of the substrate 140 as indicated by an arrow shown in FIG. 10B in a state as shown in FIG. 10B where the substrate 140 is fixedly held, water 130B between the semiconductor film 100 and the substrate 140 serves as a lubricant which permits the semiconductor film 100 to slide on the substrate 140. As described above, the semiconductor film 100 is drawn out from the position above the substrate 140 so that the semiconductor film 100 is separated from the substrate 140 (see FIG. 10C). The above-mentioned method permits the semiconductor film 100 to be divided into sections each having a thickness of 10 .mu.m and a size of 10 cm.times.10 cm.
FIG. 11 is a structural view showing a conventional manufacturing apparatus for embodying the method of manufacturing the semiconductor apparatus. Similarly to the foregoing method, the apparatus has been disclosed in Japanese Patent Application No. 6-162452. Referring to FIG. 11, reference numeral 100 represents a semiconductor film, 110 represents a through hole, 140 represents a substrate, 210 represents a first container and 211 represents an upper portion of the first container 210. Reference numeral 212 represents a taper of the first container 210. Reference numeral 213 represents a lower portion of the first container 210. Reference numeral 300 represents an upper room, 310 represents a lower room, 400 represents a second container and 410 represents a cover for sealing up the second container 400.
In a case where the semiconductor film 100 is larger than the substrate 140 as shown in FIG. 11, the width of the lower room 310 is made to be smaller than the width of the upper room 300 so that introduction of the semiconductor film 100 is permitted and that of the substrate 140 is inhibited. Since force for fixing the semiconductor film 100 to the substrate 140 is lost after the separation layer has been removed by etching, the semiconductor film 100 is, attributable to the gravity, moved along the surface of the substrate 140 toward the lower room 310. Since the substrate 140 has a size with which the movement of the substrate 140 into the lower room 310 is inhibited, only the semiconductor film 100 is moved into the lower room 310. As a result, the separation of the semiconductor film 100 from the substrate 140 can be performed.
Since the conventional method and apparatus for manufacturing a semiconductor apparatus have been structured as described above, completion of the process for etching the separation layer does not result in the semiconductor film and the substrate being completely separated from each other. Since the semiconductor film and the substrate are, in many cases, in close contact with each other, an external force has been required to be applied to completely separate the semiconductor film and the substrate from each other. There arises another problem in that time required to complete the process cannot be shortened and the surface of the semiconductor film is roughened excessively because the semiconductor film is immersed in the etchant for a long time. Since the conventional manufacturing apparatus is not provided with a function for again liquefying vapor of the hydrofluoric acid etchant, there arise problems in that the life of the etchant is unsatisfactorily short and that an excessively large quantity of the etchant is required.
As a result, the cost performance has been unsatisfactory in a case where the semiconductor film and the substrate are separated from each other in the mass production level.